1. Field of the Invention
The present invention relates to an image forming apparatus and a method of assembling the same.
2. Discussion of the Background
An image forming apparatus of the type forming a latent image on a rotatable image carrier with a writing device, developing the latent image to produce a corresponding toner image and transferring the toner image to a paper or similar recording medium is conventional. The problem with this type of image forming apparatus is that when any one of the writing devices and other process members arranged around the image carrier is not accurately located at a preselected position, it lowers the quality of images. Particularly, in a color image forming apparatus transferring toner images of different colors one above the other, the displacement of any process member brings the colors out of register.
Japanese Patent Laid-Open Publication No. 8-62916, for example, discloses a method for accurately positioning the above process members. The method uses mount portions included in side walls forming a part of the apparatus body. Support portions supporting opposite ends of a photoconductive element, an optical unit and other structural elements are mounted on the mount portions, so that the photoconductive element and optical unit are accurately positioned relative to each other.
The above mount portion scheme will be successful so long as the side walls of the apparatus body are light weight and small size. The side walls, however, usually have a substantial size and a substantial weight because they are major constituents for mounting major structural elements. Mounting the photoconductive element, optical unit and others on such heavy and bulky side walls would, if not impossible, complicate assembly, considering the cost on a quantity production basis.